Brittany Maynard's Husband Reveals Why She Chose Him to Tell Her Life Story

For Dan Diaz, the two years since his wife Brittany Maynard died have been about keeping the promises he made to her — large and small.

This week he kept a big one. On Monday, word leaked out that Good Universe had optioned the rights to Maynard’s story as well as Diaz’s, who will also be an executive producer on the film.

Diaz, who has been working full time to get right-to-die legislation passed in several states, had not wanted the news to come out until after the Nov. 8 election but says it’s all part of the same goal-protecting his wife’s legacy and carrying on the work she’d just started doing before she died.

“It’s a way that I can share the true story of Brittany so that the audience gets the true picture of who she was,” Diaz, 44, tells PEOPLE. “Most importantly, it will help move [aid in dying] legislation forward by sharing the reality of what Brittany was going through and the logic of the decisions she was making, that being her true legacy.”

Nathan Kahane, co-founder of Good Universe, said: “We are incredibly honored that Dan has entrusted us with helping to tell Brittany’s incredibly courageous and heroic story through film. Dan’s work in honoring his wife’s legacy is truly inspirational and we hope a film brings more awareness to the issue. ”

Maynard, 29, who had terminal brain cancer, ended her own life on Nov. 1, 2014 with medication prescribed to her by her doctor in Portland, Oregon. She and her husband had moved to the state from California so Maynard could access its Death with Dignity law.

She quickly became the face of the controversial right-to-die movement – and the subject of countless news stories.

So concerned was Maynard about her story being told the way she wanted it to be told, she sat down with an attorney the week before she died and signed over the rights to her life story to Dan.

“No one else can tell my story, Dan, except for you,” she told her husband, according to a new statement released by Diaz Friday. “You are the only one that has been here for me the entire time and you are the only one that can share the meaningful private moments that I would want shared.”

She also told him, “My mother might be the biggest problem regarding protecting my story,” according to the statement.

Because of her concerns, she made sure to tell her mother, Deborah Ziegler, that she did not want her to write a book about her life, Diaz says. She then prepared a statement for Diaz to release should her mother write a book, anyway.

Courtesy Compassion & Choices

Courtesy Compassion & Choices

On Oct. 14, Good Housekeepingran an excerpt of Ziegler’s new book, “Wild and Precious Life,” in which she shares the “mostly untold story” of her daughter’s last year of life, according to Simon & Schuster’s description of the book.

So Diaz released his late wife’s statement.

“I love my mother very much, but I don’t want her to be a storyteller about me,” Maynard said. “She’s been a great mom and I wouldn’t be here without her but I don’t want her to write about me. It is not her place to do so.”

Diaz believes Maynard would not be happy with the way she’s portrayed in the book.

“Brittany was very specific about how her story should be told and she went to great lengths to prevent her story from being misrepresented,” says Diaz, who says he was not approached for factchecking for Ziegler’s book.

“I was at Brittany’s side during our time at the rental house in Portland,” he says. “There are dozens of important scenes that were not even included and those are the moments Brittany’s parents weren’t around for because they were absent from the Portland house for weeks at a time. They weren’t there for most of the last week of her life.”

Ziegler declined to comment to PEOPLE but told the Today Show Monday she was not aware of her daughter’s wishes.

“When she talked about me working for the cause, she said, ‘Use your strength,’ ” Ziegler told the show. “She never said anything to me about that so I don’t know what to think of this statement except that Brittany said many, many things in those last days, and I again go back to honoring the Brittany who I knew, not the brain tumor Brittany.”

Paul Olsewski, vice President and director of publicity for Atria Books (which is owned by Simon & Schuster), Ziegler’s publisher, defended the book and its contents in a statement provided to PEOPLE.

“As we approach the second anniversary of Brittany’s death, WILD AND PRECIOUS is a beautiful tribute to her life and honors Deb’s promise to her to carry forward her legacy and the discussion of death with dignity,” the statement said. “The book recounts a lifetime of experiences, and unless you’ve lived life as Deb has – a mother enduring the loss of her only child – it seems unlikely anyone would be able to know what she experienced.”

Posting the response to Ziegler’s book is something Diaz did with “a heavy heart,” he says in the statement.

But with this, as with his work as a consultant for Compassion & Choices, he’s simply making sure he keeps the promises he made to his wife.

“Brittany shared her story so that terminally ill individuals in her predicament could have the option of applying for medical aid in dying in order to have a gentle dying process without needing to leave their home for another state as we did,” he wrote. “I continue to advocate for this end-of-life option to honor Brittany’s legacy and because I firmly believe in this basic human right.”